--2016 Financial Outlook Expects Full-Year 2016 GAAP EPS to be Between $1.96 and $2.23; Expects Non-GAAP EPS to be Between $3.60 and $3.75, Including an Approximately 4 Percent Negative Impact from Foreign Exchange

--Anticipates Full-Year 2016 Worldwide Sales to be Between $38.7 Billion and $40.2 Billion, Including an Approximately 3 Percent Negative Impact from Foreign Exchange

"The past year was one of considerable progress and execution for
Merck," said Kenneth C. Frazier, chairman and chief executive officer,
Merck. "Im excited by the near-term opportunities, as we continue
launching important new products like ZEPATIER and KEYTRUDA while
augmenting and advancing our pipeline."

Non-GAAP (generally accepted accounting principles) earnings per share
(EPS) of $0.93 for the fourth quarter and $3.59 for the full year of
2015 exclude acquisition- and divestiture-related costs, restructuring
costs and certain other items, as well as a net charge to settle Vioxx
shareholder class action litigation.

A reconciliation of GAAP to non-GAAP net income and EPS is provided in
the tables that follow.

(1) Merck is providing certain 2015 and 2014 non-GAAP
information that excludes certain items because of the nature of these
items and the impact they have on the analysis of underlying business
performance and trends. Management believes that providing this
information enhances investors understanding of the companys
performance. This information should be considered in addition to, but
not in lieu of, information prepared in accordance with GAAP. For
description of the items, see Tables 2a and 2b, including the related
footnotes, attached to this release.

(2) Net income attributable to Merck & Co., Inc.

(3) Represents the difference between calculated GAAP EPS and
calculated non-GAAP EPS, which may be different than the amount
calculated by dividing the impact of the excluded items by the
weighted-average shares for the period.

(4) Includes expenses for the amortization of intangible assets
recognized as a result of acquisitions, intangible asset impairment
charges and expense or income related to changes in the estimated fair
value measurement of liabilities for contingent consideration. Also
includes integration costs, as well as transaction and certain other
costs related to business acquisitions and divestitures.

(5) Includes the estimated tax impact on the reconciling items.
In addition, amounts for fourth-quarter and full-year 2015 include net
benefits of $40 million and $410 million, respectively, related to the
settlement of certain federal income tax issues. Additionally, amount
for full-year 2014 includes a net benefit of $517 million recorded in
connection with AstraZenecas option exercise, as well as a benefit of
approximately $300 million associated with a capital loss generated in
the first quarter.

Additional Executive Commentary

"In 2016 we will build upon the strong foundation we established last
year. We will continue to invest resources to launch and grow our
strongest brands, support the most promising internal assets, enhance
our pipeline with the best available external science and maintain a
balanced and differentiated portfolio, with the goal of delivering
long-term growth and shareholder value," said Frazier.

"We will pursue numerous filings and approvals in 2016," said Dr. Roger
M. Perlmutter, president, Merck Research Laboratories. "For example, we
view KEYTRUDA as foundational in the next-generation treatment of
malignant disease, and hence have embarked upon an exceptionally broad
development program for this agent, with registration-enabling studies
underway in more than a dozen tumor types. We will also pursue more than
100 studies involving combinations of KEYTRUDA with other drugs."

"The fourth quarter was a strong finish to a solid year of execution. We
expect this momentum to continue into 2016, as we further innovate in
our labs, invest behind our launches and continue our focus on
disciplined resource allocation and continuous productivity to deliver a
leveraged P&L and shareholder returns," said Robert Davis, chief
financial officer, Merck.

Select Business Highlights

Worldwide sales were $10.2 billion for the fourth quarter of 2015, a
decrease of 3 percent compared with the fourth quarter of 2014,
including a 7 percent negative impact from foreign exchange and a 3
percent net positive impact primarily from the acquisition of Cubist
Pharmaceuticals, Inc. (Cubist). Full-year 2015 worldwide sales were
$39.5 billion, a decrease of 6 percent compared with the full year of
2014, including a 6 percent negative impact from foreign exchange and a
3 percent net negative impact resulting from the divestiture of the
Consumer Care business and select products, partially offset by the
Cubist acquisition.

The following table reflects sales of the companys top pharmaceutical
products, as well as total sales of Animal Health and Consumer Care
products.

The company continued to make steady progress in advancing its
late-stage pipeline, achieving key regulatory approvals and expanded
indications for multiple products across its portfolio.

--
The U.S. Food and Drug Administration (FDA) approved
ZEPATIER (elbasvir and grazoprevir), a once-daily, fixed-dose
combination tablet for the treatment of adult patients with chronic
hepatitis C virus (HCV) genotype (GT) 1 or GT4 infection, with or
without ribavirin. ZEPATIER was approved for use in a broad range of
chronic HCV patients, including those with compensated cirrhosis,
renal impairment of any degree and HIV-1/HCV co-infection.

--
Merck significantly advanced its development program for KEYTRUDA
(pembrolizumab), an anti-PD-1 therapy for the treatment of metastatic
non-small cell lung cancer (NSCLC) in previously treated patients
whose tumors express PD-L1, as well as advanced melanoma.
--
The FDA approved
KEYTRUDA for the treatment of patients with metastatic NSCLC whose
tumors express PD-L1 as determined by an FDA-approved test and who
have disease progression on or after platinum-containing
chemotherapy across both squamous and non-squamous metastatic
NSCLC.

--
The FDA approved
an expanded indication for KEYTRUDA for the first-line treatment
of patients with unresectable or metastatic melanoma regardless of
BRAF status and an update to the product labeling for KEYTRUDA for
the treatment of patients with ipilimumab-refractory advanced
melanoma.

--
KEYTRUDA received
a third Breakthrough Therapy Designation from the FDA for the
treatment of patients with microsatellite instability high
metastatic colorectal cancer.

--
Results from the pivotal KEYNOTE-010 study were
published in The Lancet and presented at the European
Society for Medical Oncology Asia 2015 Congress, showing superior
overall survival compared to chemotherapy in patients with
previously treated advanced NSCLC whose tumors express PD-L1.
Based on these data, the company has submitted a supplemental
Biologics License Application to the FDA and a Marketing
Authorization Application (MAA) to the European Medicines Agency
(EMA).

--
During the fourth quarter of 2015, the company entered into
collaborations with GSK
and Amgen.
Additionally, the company extended an existing
collaboration with Eli Lilly and Company (Lilly) and entered
into a new
collaboration with Lilly to study KEYTRUDA in combination
settings.

--
The KEYTRUDA clinical trials program currently includes more than
30 tumor types in more than 200 clinical trials, including more
than 100 trials that combine KEYTRUDA with other cancer
treatments. Registration-enabling trials of KEYTRUDA are currently
enrolling patients with melanoma, NSCLC, head and neck cancer,
bladder cancer, gastric cancer, colorectal cancer, esophageal
cancer, Hodgkin lymphoma, multiple myeloma and breast cancer, and
further trials are being planned for other malignancies.

--
The company strengthened its oncology pipeline by acquiring
IOmet Pharma Ltd (IOmet) in early 2016. IOmet is a drug discovery
company focused on the development of innovative medicines for the
treatment of cancer, with a particular emphasis on the fields of
cancer immunotherapy and cancer metabolism.

--
BRIDION (sugammadex) Injection 100 mg/mL was approved
by the FDA for the reversal of neuromuscular blockade induced by
rocuronium bromide and vecuronium bromide in adults undergoing surgery.

--
The Biologics License Application for bezlotoxumab, an investigational
antitoxin for the prevention of Clostridium difficile (C.
difficile) infection recurrence, was accepted
by the FDA for priority review with a PDUFA action date of July 23,
2016. The company also has filed a MAA for bezlotoxumab with the EMA
that is currently under review.

Pharmaceutical Revenue Performance

Fourth-quarter pharmaceutical sales declined 4 percent to $9.0 billion,
including an 8 percent negative impact from foreign exchange. Excluding
the impact of exchange, growth was driven by sales in hospital acute
care, oncology and vaccines. Growth in hospital acute care was driven by
the addition of the Cubist portfolio and sales growth of certain inline
brands. Growth in oncology reflects higher sales of KEYTRUDA. Growth in
vaccines reflects higher sales of GARDASIL 9 (Human Papillomavirus
9-valent Vaccine, Recombinant), a vaccine to prevent cancers and other
diseases caused by HPV, reflecting an increase in sales in the United
States primarily due to public sector purchases, and higher sales of
PROQUAD (Measles, Mumps, Rubella and Varicella Vaccine Live) driven by
the timing of sales activity related to the Pediatric Vaccine Stockpile
of the U.S. Centers for Disease Control and Prevention.

Fourth-quarter pharmaceutical sales reflect a decrease in PNEUMOVAX 23
(pneumococcal vaccine polyvalent), due to near-term market dynamics in
the United States and the timing of vaccinations linked to the National
Immunization Program in Japan, as well as lower sales in the diabetes
franchise of JANUVIA (sitagliptin)/JANUMET (sitagliptin and metformin
HCl), medicines that help lower blood sugar in adults with type 2
diabetes, driven in large part by an expected decline due to the timing
of customer purchases in the third quarter of 2015. Pharmaceutical sales
also reflect declines in REMICADE (infliximab), a treatment for
inflammatory diseases, due to loss of exclusivity and the accelerating
impact of biosimilar competition in the companys marketing territories
in Europe, and PEGINTRON (peginterferon alfa-2b), a medicine to treat
chronic HCV.

Animal Health sales totaled $830 million for the fourth quarter of 2015,
a decrease of 6 percent compared with the fourth quarter of 2014,
including a 14 percent negative impact from foreign exchange. Worldwide
sales for the full year of 2015 were $3.3 billion, a decrease of 4
percent, including a 13 percent negative impact from foreign exchange.
Excluding the impact of exchange, growth in both periods was primarily
driven by an increase in sales of companion animal products, including
continued strong growth from BRAVECTO (fluralaner), a chewable tablet
that kills fleas and ticks in dogs for up to 12 weeks, and aqua and
swine products.

Fourth-Quarter and Full-Year 2015 Expense and Other Information

The tables below present selected expense information for the fourth
quarter and full year of 2015.

The gross margin was 62.3 percent for the fourth quarter of 2015
compared to 64.2 percent for the fourth quarter of 2014, reflecting 12.5
and 10.4 unfavorable percentage point impacts, respectively, from the
acquisition- and divestiture-related costs and restructuring costs noted
above. The gross margin was 62.2 percent for the full year of 2015
compared to 60.3 percent for the full year of 2014, reflecting 13.2 and
13.6 unfavorable percentage point impacts, respectively, from the
acquisition- and divestiture-related costs and restructuring costs noted
above. The rate increases in non-GAAP gross margin for the fourth
quarter and full year of 2015 reflect the favorable impact of foreign
exchange and lower inventory write-offs.

Marketing and administrative expenses, on a non-GAAP basis, were $2.6
billion in the fourth quarter of 2015, a decrease from $2.8 billion in
the same period of 2014, which was primarily driven by the favorable
impact of foreign exchange and operational efficiencies, partially
offset by investments in key brands. Full-year 2015 marketing and
administrative expenses, on a non-GAAP basis, were $9.8 billion, a
decrease from $11.0 billion in 2014, which was primarily driven by the
favorable impact of foreign exchange and the sale of the Consumer Care
business, partially offset by investments in key brands.

Research and development (R&D) expenses, on a non-GAAP basis, were $1.8
billion in the fourth quarter of 2015, a 2 percent decrease compared to
the fourth quarter of 2014. Full-year R&D expenses in 2015, on a
non-GAAP basis, were $6.6 billion, an increase from $6.5 billion in 2014.

Other (income) expense, net, was $905 million of expense in the fourth
quarter of 2015 compared to $10.6 billion of income in the fourth
quarter of 2014 and $1.5 billion of expense for the full year of 2015
compared to $11.6 billion of income for the full year of 2014. Other
(income) expense, net for the fourth quarter and full year of 2015
includes $161 million and $876 million, respectively, of foreign
exchange losses related to the revaluation of the companys net monetary
assets in Venezuela and a $680 million net charge to settle Vioxx
shareholder class action litigation. Other (income) expense, net in both
the fourth quarter and full year of 2014 includes an $11.2 billion gain
on the divestiture of the Consumer Care business and a $628 million loss
on the extinguishment of debt.

The GAAP effective tax rates of (20.4) percent for the fourth quarter of
2015 and 17.4 percent for the full year of 2015 reflect the impacts of
acquisition- and divestiture-related costs, restructuring costs and
certain other items, including the impact of the net charge to settle
Vioxx shareholder class action litigation being fully deductible at
combined U.S. federal and state tax rates, as well as the unfavorable
impact of non-deductible foreign exchange losses related to Venezuela.
In addition, the GAAP effective tax rates for the fourth quarter and
full year of 2015 include net benefits of $40 million and $410 million,
respectively, related to the settlement of certain federal tax issues.
The non-GAAP effective tax rates, which exclude these items, were 16.4
percent for the fourth quarter and 21.7 percent for the full year of
2015. Both the GAAP and non-GAAP effective tax rates for the fourth
quarter and full year of 2015 include the favorable impact of tax
legislation, including the renewal of the R&D tax credit, enacted in the
fourth quarter of 2015.

Financial Outlook

Merck expects its full-year 2016 GAAP EPS to be between $1.96 and $2.23.
Merck expects its full-year 2016 non-GAAP EPS to be between $3.60 and
$3.75, including an approximately 4 percent negative impact from foreign
exchange. The non-GAAP range excludes acquisition- and
divestiture-related costs and costs related to restructuring programs.

At mid-January 2016 exchange rates, Merck anticipates full-year 2016
revenues to be between $38.7 billion and $40.2 billion, including an
approximately 3 percent negative impact from foreign exchange.

In addition, the company expects full-year 2016 non-GAAP marketing and
administrative expenses to be below 2015 levels and R&D expenses to be
modestly above 2015 levels.

The company anticipates its full-year 2016 non-GAAP tax rate will be in
the range of 21.5 to 22.5 percent, including a 2016 R&D tax credit.

A reconciliation of anticipated 2016 EPS, as reported in accordance with
GAAP to non-GAAP EPS that excludes certain items, is provided in the
table below.

As of Dec. 31, 2015, Merck had approximately 68,000 employees worldwide.

Earnings Conference Call

Investors, journalists and the general public may access a live audio
webcast of the call today at 8:00 a.m. EST on Mercks website at http://www.merck.com/investors/events-and-presentations/home.html .
Institutional investors and analysts can participate in the call by
dialing (706) 758-9927 or (877) 381-5782 and using ID code number
4404803. Members of the media are invited to monitor the call by dialing
(706) 758-9928 or (800) 399-7917 and using ID code number 4404803.
Journalists who wish to ask questions are requested to contact a member
of Mercks Media Relations team at the conclusion of the call.

About Merck

Todays Merck is a global health care leader working to help the world
be well. Merck is known as MSD outside the United States and Canada.
Through our prescription medicines, vaccines, biologic therapies and
animal health products, we work with customers and operate in more than
140 countries to deliver innovative health solutions. We also
demonstrate our commitment to increasing access to health care through
far-reaching policies, programs and partnerships. For more information,
visit www.merck.com
and connect with us on Twitter,
Facebook,
YouTube
and LinkedIn.

Forward-Looking Statement of Merck & Co., Inc., Kenilworth, N.J., USA

This news release of Merck & Co., Inc., Kenilworth, N.J., USA (the
"company") includes "forward-looking statements" within the meaning of
the safe harbor provisions of the U.S. Private Securities Litigation
Reform Act of 1995. These statements are based upon the current beliefs
and expectations of the companys management and are subject to
significant risks and uncertainties. There can be no guarantees with
respect to pipeline products that the products will receive the
necessary regulatory approvals or that they will prove to be
commercially successful. If underlying assumptions prove inaccurate or
risks or uncertainties materialize, actual results may differ materially
from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry
conditions and competition; general economic factors, including interest
rate and currency exchange rate fluctuations; the impact of
pharmaceutical industry regulation and health care legislation in the
United States and internationally; global trends toward health care cost
containment; technological advances, new products and patents attained
by competitors; challenges inherent in new product development,
including obtaining regulatory approval; the companys ability to
accurately predict future market conditions; manufacturing difficulties
or delays; financial instability of international economies and
sovereign risk; dependence on the effectiveness of the companys patents
and other protections for innovative products; and the exposure to
litigation, including patent litigation, and/or regulatory actions.

The company undertakes no obligation to publicly update any
forward-looking statement, whether as a result of new information,
future events or otherwise. Additional factors that could cause results
to differ materially from those described in the forward-looking
statements can be found in the companys 2014 Annual Report on Form 10-K
and the companys other filings with the Securities and Exchange
Commission (SEC) available at the SECs Internet site (www.sec.gov).

(3) Other (income) expense, net in the fourth quarter and full year of
2015 includes a $680 million net charge to settle VIOXX shareholder
class action litigation, as well as a $147 million gain on the
divestiture of the companys remaining ophthalmics business in
international markets. Other (income) expense, net in the fourth quarter
and full year of 2015 includes foreign exchange losses of $161 million
and $876 million, respectively, to revalue the companys net monetary
assets in Venezuela. Other (income) expense, net for the full year of
2015 also includes a $250 million gain on the sale of certain migraine
clinical development programs.

Other (income) expense, net in the fourth quarter and full year of 2014
includes an $11.2 billion gain on the divestiture of Mercks Consumer
Care business and a $628 million loss on the extinguishment of debt.
Other (income) expense, net for the full year of 2014 also includes a
gain of $741 million related to AstraZenecas option exercise, a gain of
$480 million on the divestiture of certain ophthalmic products in
several international markets, and a gain of $204 million related to the
divestiture of the companys Sirna Therapeutics, Inc. subsidiary, as
well as a $93 million goodwill impairment charge related to the
companys joint venture with Supera Farma Laboratorios S.A.

Other (income) expense, net includes equity income from affiliates.
Prior period amounts have been reclassified to conform to the current
presentation.

(4) The effective income tax rates for the fourth quarter and full year
of 2015 reflect the impact of the net charge to settle VIOXX shareholder
class action litigation being fully deductible at combined U.S. federal
and state tax rates, as well as the favorable impact of tax legislation
enacted in the fourth quarter of 2015, partially offset by the
unfavorable impact of non-deductible foreign exchange losses recorded in
connection with the revaluation of the companys net monetary assets in
Venezuela. The effective income tax rates for the fourth quarter and
full year of 2015 also reflect net benefits of $40 million and $410
million, respectively, related to the settlement of certain federal
income tax issues.

The effective income tax rates for the fourth quarter and full year of
2014 include the impact of the gain on the divestiture of Mercks
Consumer Care business being taxed primarily at combined U.S. federal
and state tax rates. The effective income tax rates for the fourth
quarter and full year of 2014 also reflect the favorable impact of tax
legislation enacted in the fourth quarter of 2014. In addition, the
effective income tax rate for the full year of 2014 reflects a net
benefit of $517 million recorded in connection with AstraZenecas option
exercise, as well as a benefit of approximately $300 million associated
with a capital loss generated in the first quarter of 2014.

Merck is providing non-GAAP information that excludes certain items
because of the nature of these items and the impact they have on the
analysis of underlying business performance and trends. Management
believes that providing this information enhances investors
understanding of the companys performance. This information should be
considered in addition to, but not in lieu of, information prepared in
accordance with GAAP.

(1) Amounts included in materials and production costs reflect $1.1
billion of expenses for the amortization of intangible assets recognized
as a result of acquisitions, as well as $29 million of amortization of
purchase accounting adjustments to inventories as a result of the Cubist
acquisition, and $33 million of impairment charges on intangible assets.
Amounts included in marketing and administrative expenses reflect
integration, transaction and certain other costs related to business
acquisitions, including severance costs which are not part of the
companys formal restructuring programs, as well as transaction and
certain other costs related to divestitures. Amounts included in
research and development expenses primarily reflect income of $25
million resulting from a reduction in the estimated fair value of
liabilities for contingent consideration. Amounts included in other
(income) expense, net represent goodwill impairment charges related to
certain of Mercks Healthcare Services businesses.

(2) Amounts primarily include employee separation costs and accelerated
depreciation associated with facilities to be closed or divested related
to activities under the companys formal restructuring programs.

(3) Primarily reflects a $680 million net charge to settle VIOXX
shareholder class action litigation, foreign exchange losses of $161
million to revalue the companys net monetary assets in Venezuela and a
$147 million gain on the divestiture of the companys remaining
ophthalmics business in international markets.

(4) Other (income) expense, net includes equity income from affiliates.

(5) Represents the estimated tax impact on the reconciling items, as
well as a net benefit of $40 million on the settlement of certain
federal income tax issues.

Merck is providing non-GAAP information that excludes certain items
because of the nature of these items and the impact they have on the
analysis of underlying business performance and trends. Management
believes that providing this information enhances investors
understanding of the companys performance. This information should be
considered in addition to, but not in lieu of, information prepared in
accordance with GAAP.

(1) Amounts included in materials and production costs reflect $4.7
billion of expenses for the amortization of intangible assets recognized
as a result of acquisitions, as well as $105 million of amortization of
purchase accounting adjustments to inventories as a result of the Cubist
acquisition, and $45 million of impairment charges on intangible assets.
Amounts included in marketing and administrative expenses reflect
integration, transaction and certain other costs related to business
acquisitions, including severance costs which are not part of the
companys formal restructuring programs, as well as transaction and
certain other costs related to divestitures. Amounts included in
research and development expenses reflect $63 million of in-process
research and development (IPR&D) impairment charges and income of $24
million resulting from a reduction in the estimated fair value of
liabilities for contingent consideration. Amounts included in other
(income) expense, net represent goodwill impairment charges related to
certain of Mercks Healthcare Services businesses.

(2) Amounts primarily include employee separation costs and accelerated
depreciation associated with facilities to be closed or divested related
to activities under the companys formal restructuring programs.

(3) Primarily reflects foreign exchange losses of $876 million to
revalue the companys net monetary assets in Venezuela, a $680 million
net charge to settle VIOXX shareholder class action litigation, a $250
million gain on the divestiture of certain migraine clinical development
programs and a $147 million gain on the divestiture of the companys
remaining ophthalmics business in international markets.

(4) Other (income) expense, net includes equity income from affiliates.

(5) Represents the estimated tax impact on the reconciling items, as
well as a net benefit of $410 million on the settlement of certain
federal income tax issues.

Sum of quarterly amounts may not equal year-to-date amounts due to
rounding.

(1) Only select products are shown.

(2) Cubicin results for the first quarter 2015 represent
sales for the two months following Mercks acquisition of Cubist.
Cubicin sales for 2014 represent the previous licensing agreement in
Japan prior to the acquisition.

(3) Includes Pharmaceutical products not individually shown
above. Other Vaccines sales included in Other Pharmaceutical were $78
million, $76 million, $99 million, and $148 million for the first,
second, third, and fourth quarters of 2015, respectively. Other Vaccines
sales included in Other Pharmaceutical were $98 million, $76 million,
$116 million and $88 million for the first, second, third and fourth
quarters of 2014, respectively.

(4) On October 1, 2014, the company divested the Consumer
Care business.

(5) Other revenues are comprised primarily of alliance
revenue, third-party manufacturing sales and miscellaneous corporate
revenues, including revenue hedging activities. On June 30, 2014,
AstraZeneca exercised its option to buy Mercks interest in a subsidiary
and through it, Mercks interest in Nexium and Prilosec. As a result,
the company no longer records supply sales for these products. Other
revenues in the first quarter 2014 include $232 million of revenue
recognized in connection with the sale of U.S. Saphris rights.